Source: Justice Department to investigate Chicago police

CHICAGO -- The U.S. Justice Department is expected to launch a wide-ranging investigation this week into the patterns and practices of the Chicago Police Department after recent protests over a video showing a white Chicago police officer shooting a black teenager 16 times, according to a person familiar with the matter.

The person was not authorized to discuss the investigation publicly before it was announced and spoke to The Associated Press on condition of anonymity.

The civil-rights probe follows others recently in Baltimore and Ferguson, Missouri, and comes as the police department and Mayor Rahm Emanuel are under scrutiny over their handling of the October 2014 death of 17-year-old Laquan McDonald. Officer Jason Van Dyke was charged with first-degree murder Nov. 24, more than a year after the killing and just hours before the release of police dashboard camera footage showing the officer shooting the teenager.

The video shows McDonald veering away from officers on a four-lane street when Van Dyke, seconds after exiting his squad car, opens fire from close range.

The officer continues shooting after McDonald crumples to the ground and is barely moving. The video does not include sound, which authorities have not explained.

The Chicago City Council signed off on a $5 million settlement with McDonald's family even before the family filed a lawsuit, and city officials fought in court for months to keep the video from being released publicly.